All water cooled automobile engines are provided with expansion holes in the water jacket which are plugged with freeze plugs which theoretically, if not in practice, pop out upon the accidental freezing of the water in the water jacket to preserve the water jacket itself. Over a period of time, these freeze plugs become rusty and weak and must be knocked out and replaced. Different techniques are available for knocking the plugs out, and as considerable force and impact is required to drive the plugs into place, tools adapted to this purpose have been developed.
Typically, these tools include a head on the end of a bent rod which is manually pounded with a hammer or mallet on its free end. This approach to the problem is imperfect in that to orient the tool with one hand and swing a hammer with the other often is quite awkward and not infrequently will require two people to do thejob rather than a single mechanic which would otherwise be required. This difficulty is caused by the very close spaces and often awkwardly oriented freeze plug holes which the automotive mechanic faces when trying to reinstall the plugs.